This application claims the benefit of Japanese Applications No. 2001-371736 filed in Japan on Dec. 5, 2001, and No. 2001-401829 filed in Japan on Dec. 28, 2001, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a camera having a so-called electronic viewfinder in which a liquid crystal display element is incorporated, or a camera having a liquid crystal display. More particularly, the present invention relates to the location and structure of the electronic viewfinder in the camera, and the structure for bearing the liquid crystal display and the location of the liquid crystal display.
2. Description of Related Art
In recent years, a demand for a so-called digital camera that records and reproduces an object image that is converged by an imaging optical system and then formed by a CCD (charge-transfer imaging device) has increased along with the prevalence of electronic equipment including a personal computer.
In this type of digital camera, the CCD forms an object image converged by the imaging optical system so as to produce a video signal. Based on the image signal, the object image is displayed on a display such as an LCD (liquid crystal display) so that a photographic scene can be verified. In the past, there has been a great demand for a compact and power-saving camera.
A digital camera has been requested to have the capability of a viewfinder, in order to check an image during photography. Moreover, inclusion of a large-sized display is preferred in order to view a recorded photographic image.
Moreover, the capability of a viewfinder can be, as already known, realized with an optical viewfinder or an electronic viewfinder.
However, when the capability of a viewfinder is realized by using an optical viewfinder, if a photographic lens is a zoom lens, a mechanism for interlocking the viewfinder with the photographic lens is complex. This makes it hard to realize a compact and thin camera. Moreover, a viewfinder of a single-lens reflex type may be constructed. In this case, the position of the viewfinder relative to a photographic lens is restricted. The restriction leads to a critical condition that must be satisfied for the pursuit of a compact camera.
FIG. 20 is a longitudinal sectional view showing an example of a conventional camera in which the capability of a viewfinder is realized with inclusion of an electronic viewfinder.
As shown in FIG. 20, a camera 100 of this type has a photographic lens 102, a control circuit board 103, a liquid crystal display (hereinafter, a TFT panel) 104, an electronic viewfinder unit 105, and a power circuit board 107 included inside a camera armor 101 forming a camera housing.
In general, the photographic lens 102 is located in the lower part of the inside of the camera armor 101. The photographic lens 102 picks up an object image using the optical system and converges the image light on an imaging device such as a CCD mounted on the control circuit board 103. The control circuit board 103 is located near the back of the camera armor 101. Optical members including the CCD, various electronic parts, and a signal processing circuit for converting the imaging light into a video signal are mounted on the control circuit board 103.
Behind the control circuit board 103 is a first TFT panel 104, on which a formed image is displayed, so that the display surface thereof will be bared on the back of the camera armor 101.
On the other hand, the electronic viewfinder unit 105 has the capability of a viewfinder to permit viewing of an object image during photography. The electronic viewfinder unit 105 includes at least a second TFT panel 106 on which a formed image or an object image is displayed, and an eyepiece 105a through which the image displayed on the second panel TFT is viewed. The electronic viewfinder unit 105 is located in the upper part of the inside of the camera armor 101. The power circuit board 107 for strobe lighting or the like is interposed between the electronic viewfinder unit 105 and the photographic lens 102.
The first TFT panel 104 and control circuit board 103 are electrically connected to each other via a connector 108b formed on the control circuit board 103 and a flexible circuit board 104a. Moreover, the second TFT panel 106 and control circuit board 103 are electrically connected to each other via a flexible circuit board 106a routed from below the electronic viewfinder unit 105 and a connector 108a mounted on the back of the control circuit board 103.
As mentioned above, in the structure attempting to realize the capability of a viewfinder with inclusion of an electronic viewfinder, unlike a camera structured to have an optical viewfinder and a zoom lens, the position of the electronic viewfinder within the camera is not restricted and a complex interlocking mechanism such as a zooming mechanism is not included. However, in the camera 100 shown in FIG. 20, a predetermined optical length must be ensured for light traveling between the second TFT panel 106 and eyepiece 105a included in the electronic viewfinder unit 105. The illustrated space is occupied, causing a critical obstacle to realization of a thin camera.
When the capability of a viewfinder is realized with inclusion of an optical viewfinder, if a zoom lens is included, it is hard to realize a compact and thin design for conventional cameras because of a complex mechanism for interlocking the viewfinder with a photographic lens. A single-lens reflex type viewfinder may be constructed. However, in this case, the position of the viewfinder relative to the photographic lens is restricted, and this restriction becomes a critical condition that must be satisfied in pursuit of a compact camera. It is therefore hard to realize a compact and thin camera. Otherwise, the capability of a viewfinder may be realized with inclusion of an electronic viewfinder. In this case, a complex interlocking mechanism such as a zooming mechanism is not included and the position of the viewfinder in a camera housing is not restricted. Nevertheless, an electronic viewfinder unit cannot be, like the one included in the aforesaid conventional camera, made small in size. It is therefore hard to realize a compact and thin camera.
A viewfinder unit in accordance with a similar related art has been proposed in, for example, Japanese Unexamined Patent Application Publication No. 11-243499. According to the related art, the viewfinder unit can be made smaller in size and incorporated in a compact video camera or the like.
The proposed viewfinder unit has a plurality of electronic circuit boards locked in a lens holder that is a space created behind a mirror which bends the ray axis of video light traveling from a liquid crystal display panel. The circuit boards are realized with flexible circuit boards, and can therefore be efficiently stored in a narrow space though the circuit boards require a large area. This contributes to realization of a compact camera. However, the above proposal refers to the structure for bending image light coming from the liquid crystal display panel at right angles. Mere adoption of the structure does not lead to realization of a compact and thin camera. A comprehensive idea taking a large-sized display to be located on the back of a camera into consideration realizes a satisfactorily compact and thin design. In a current situation, when the capability of a viewfinder is realized with inclusion of an electronic viewfinder, a camera cannot be designed compactly and thinly.
On the other hand, many conventional digital cameras have a liquid crystal display, which has the capability of a viewfinder, located on the back of a camera. While an object image displayed on the liquid crystal display is viewed, photography can be achieved. However, as far as high-angle or low-angle photography is concerned, an optimal angle of visibility at which an image displayed on the liquid crystal display is optimally visible may be exceeded and a display image may be hard to see. Moreover, the display image may be hard to see because of reflected sunlight.
In efforts to solve the foregoing problems, various proposals have been made in the past. For example, a digital camera has been proposed in Japanese Unexamined Patent Application Publication No. 2001-94845.
The proposed digital camera includes a turning mechanism enabling adjustment of an angle of opening or closing at which a liquid crystal display is opened or closed relative to a camera body. Moreover, the digital camera includes a light source that irradiates light to the liquid crystal display via a directive member. In the digital camera, the visibility of an image displayed on the liquid crystal display can be readily ensured, and the camera can be handled irrespective of the visibility. Therefore, the camera can offer improved maneuverability.
However, in the digital camera described in Japanese Unexamined Patent Application Publication No. 2001-94845, the liquid crystal display having the turning mechanism is handled directly in order to adjust the angle of opening or closing at which the liquid crystal device is opened or closed relative to the camera body. Using this means, every time a composition of a photograph is changed, the camera held with both hands must be released in order to directly handle the liquid crystal display. Therefore, a photographer may miss a shutter chance. Moreover, it is hard to perform high-angle or low-angle photography or to proceed with photography while changing a composition of a photograph.
Accordingly, the present invention attempts to solve the foregoing problems. The present invention provides a camera that has a viewfinder which employs a liquid crystal display, or a so-called electronic viewfinder incorporated therein, and which can be designed compactly and thinly by adopting a simple structure. The present invention also provides a camera having a liquid crystal display, and offering excellent maneuverability while being held with both hands. The camera can be designed compactly owing to adoption of a simple structure. A camera according to one aspect of the present invention consists mainly of: a display member on which an image of an object is displayed; an eyepiece located along the back of a camera housing and used to view an image displayed on the display member; and an optical path conversion member adjoining said display member and said eyepiece, and bending substantially 180xc2x0 light emitted from an image displayed on the display member so as to route the light to the eyepiece. A user can view an image of an object displayed on the display member through the eyepiece.
A camera in accordance with another aspect of the present invention consists mainly of: a first display member which is located substantially parallel to the bottom of a camera housing and on which an image of an object is displayed; an eyepiece located along the back of the camera housing and used to view the image displayed on the first display member; an optical path conversion member that adjoins the first display member and eyepiece, and that bends substantially 90xc2x0 light emitted from an image displayed on the first display member so as to route the light to the eyepiece; a second display member located along the back of the camera housing; and a circuit board interposed between the first display member and second display member and connected to both the first and second display members. A user views the image of the object displayed on the first display member through the eyepiece. Furthermore, the user can view an image displayed on the second display member.
A camera in accordance with still another aspect of the present invention consists mainly of: a display means that is selectively set to a first state in which the display means is located substantially parallel to the back of the camera and a second state in which the display means is tilted relative to the substantially parallel state, and on which an object image passed through an imaging lens is displayed; and an operating member for use in selecting the first state or the second state. The operating member can be handled with the camera held.
The other features of the present invention and the advantages thereof will be apparent from the description below.